28 research outputs found

    Diversidade genética de bovinos Brahman no Brasil por meio da análise de pedigree

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    The objective of this work was to evaluate the genetic diversity of Brahman cattle in Brazil with pedigree analysis. Genealogical records of a subpopulation were used considering all pedigree information (Pt) and the pedigree information divided into two periods (P1, from 1994 to 2004; and P2, from 2005 to 2012) or according to the raising system (Ppt, animals on pasture; or Pst, on stable). Estimates were obtained for average inbreeding coefficients, generation intervals (GI), number of equivalent known generation (CGE), number of founders (Nf), effective number of founders (fe), effective number of ancestors (fa), and founder genome equivalents (fg). The average inbreeding coefficients were 11.97, 7.79, 11.95, 11.74, and 11.31% for Pt, P1, P2, Ppt, and Pst, respectively. Average GI was 4.4 years, whereas CGE was 3.18. The fe values were similar to those of fa, which were greater than those of fg. The fe/fa and fg/fe ratios were close to 1, which indicates no genetic bottleneck and small losses by genetic drift. The genetic diversity in the Brazilian population of Brahman breed is not significantly reduced.O objetivo deste trabalho foi avaliar a diversidade genética de bovinos da raça Brahman no Brasil com análise de pedigree. Registros genealógicos de uma subpopulação foram usados, tendo-se considerado toda a informação de pedigree (Pt) e a informação de pedigree dividida em dois períodos (P1, de 1994 a 2004; e P2, de 2005 a 2012) ou de acordo com sistema de criação (Ppt, animais a pasto; ou Pst, estabulados). Foram obtidas as estimativas de coeficientes médios de endogamia, intervalos de geração (IG), número equivalente de gerações conhecidas (EGC), número de fundadores (Nf), número efetivo de fundadores (fe), número efetivo de ancestrais (fa) e número efetivo de genomas remanescentes (fg). Os coeficientes médios de endogamia foram de 11,97, 7,79, 11,95, 11,74 e 11,31% para Pt, P1, P2, Ppt e Pst, respectivamente. O IG médio foi de 4,4 anos, enquanto o EGC médio foi de 3,18. O fe foi próximo de fa, cujos valores foram maiores que os de fg. As razões fe/fa e fg/fe foram próximas de 1, o que indica ausência de gargalo genético e pequenas perdas por deriva genética. A diversidade genética na raça Brahman no Brasil não está significativamente reduzida

    Growth and yield of corn forage intercropped with marandu grass in an agrosilvopastoral system with eucalyptus

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    Corn and grass intercropping is an interesting practice, and forage plants belonging to the genus Urochloa are the most commonly used in these situations. These plants show excellent adaptation to low-fertility soil, easy establishment, considerable biomass production, as well as being an important competitor with weeds. In agrosilvopastoral systems, the yield of corn crops grown together with trees is hindered due to the reduced radiation incidence caused by tree shading. This study aimed to evaluate corn growth, light interception, and chlorophyll content when intercropped with marandu grass in an agrosilvopastoral system with one and three eucalyptus rows, and compare them with plants under full sun. The experiment was conducted in Andradina - SP (Brazil). Treatments consisted of intercropping with no eucalyptus (plants under full sun: control), one system with one eucalyptus row and another with three rows. We also assessed the effect of five distances between corn plants and eucalyptus trees (2, 4, 6, 8, and 10 m). Between eucalyptus rows, corn plants were intercropped with marandu grass. The analyzed variables were corn plant height, ear height, chlorophyll content index, light interception, dry matter, and fresh and dry forage weights. The experimental design was a randomized block in a factorial scheme plus a control, with four repetitions. Tree arrangements had no influence on corn forage, dry matter, plant height, or ear height. Lower results of yield, dry matter, plant height, and ear height were observed for plants spaced 2 m from trees. In the first two evaluations, significant differences of light interception were found for the different distances. Neither tree arrangements (one and three rows) nor the distances from the trees had any impact on corn heights, with no difference between control and the agrosilvopastoral systems. Neither plant distances from trees nor tree arrangements had an influence on chlorophyll content index of corn plants, with no difference between control and the treatments. As a result, corn growth and forage yield under agroforestry systems are similar in arrangements of 1 and 3 eucalyptus rows (15-month-old trees) and under full sun. However, corn dry matter contents were lower in systems containing trees. Intercropping corn and marandu grass in a system without trees increased light interception at harvest time, indicating a larger soil coverage. Corn forage yield and dry matter content were lower when plants were 2 m apart from eucalyptus trees since this condition provided a lower amount of light and greater competition for water and nutrients

    Estimativas de parâmetros genéticos para características de crescimento e de carcaça em ovinos de corte

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    Objetivo do presente estudo foi estimar componentes de (co)variância e parâmetros genéticos para as características de crescimento: Peso ao nascer (PN), Peso ao desmame (PD), Ganho de peso pré-desmama (GDPRÉ) e Ganho de peso pós-desmama (GDPÓS) e de carcaça: Área de olho de lombo (AOL) e Espessura de gordura subcutânea (EGS) para uma raça materna composta. Os dados utilizados foram oriundos de uma fazenda pertencente ao programa de melhoramento genético de ovino (OviGol®), coletados entre os anos de 2008 e 2011. Os efeitos ambientais considerados nos modelos foram determinados a partir de análise de variância, pela metodologia dos quadrados mínimos, considerando apenas efeitos significativos (p<0,01). Os componentes de (co)variâncias e os parâmetros genéticos para as características foram estimados pelo método da máxima verossimilhança restrita (REML), sob modelo animal, utilizando o programa REMLF90. Avaliaram-se dois modelos em análises unicaracterísticas pelo teste da razão de verossimilhança (LRT), sendo escolhido o modelo mais completo, o qual incluía como efeitos aleatórios o ambiente permanente materno e o genético aditivo. As herdabilidades diretas estimadas em análise multi-característica, sob modelo animal, foram: 0,26; 0,20; 0,23; 0,15; 0,18 e 0,10, para PN, GDPRÉ, PD, GDPÓS, AOL e EGS respectivamente. As correlações genéticas variaram de baixa a alta magnitude, sendo a mais alta entre GDPRÉ e PD (0,99) e a mais baixa entre PN e GDPÓS (0,02). Os resultados indicam que há variação genética para PN, PD e GDPRÉ, com possibilidade de seleção dentro da populaçãoThe aim of this study was to estimate the (co)variance components and genetic parameters for growth: Birth Weight (BW), Weaning Weight (WW), average daily gain pre-weaning (ADGpre) and average daily gain post-weaning (ADGpos) and carcass: Eye Muscle Area (EMA) and Fat Depth (FD) for a composite maternal breed. The data used were from a farm belonging to the breeding program for sheep (OviGol®), collected between 2008 and 2011. The environmental effects considered in models were determined from analysis of variance by least squares method, considering only significant effects (p<0.01). The components of (co)variance and genetic parameters were estimated by restricted maximum likelihood (REML), under the animal model, obtained by the REMLF90 program. Two models were tested, differentiated only by random effects in single-trait analysis of the likelihood ratio test (LRT), whichever is the more complete model, which included as random maternal permanent environmental and additive genetic. The direct heritability, analysis in multi-trait and in an animal model, was 0.26, 0.20, 0.23, 0.15, 0.18 and 0.10, for BW, ADGpre, WW, ADGpos, EMA and FT respectively. Genetic correlations ranged from low to high values, being the highest among ADGpre and WW (0.99) and lowest between BW and ADGpos (0.02). The study indicates that there is genetic variation for PN, GDPRÉ and PD, with scope for selection within populationCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

    Parâmetros genéticos para características indicadoras de eficiência reprodutiva e produtiva de ovinos da raça Santa Inês

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    Reproductive efficiency traits are of significant economic importance as they relate to the source income of sheep meat enterprise. Reliable genetic parameters are essential for selection index design and to determine the correlated response to selection that will occur in other traits in a selection index. Thus, the aim of this study was to estimate (co)variance components and parameter genetics for reproductive traits in Santa Inês sheep. Data included records of 4,742 Santa Inês sheep from Santa Inês Breeding Program of Sergipe State Sheep and Goats Breeders Association and University of São Paulo. In the first part, studied traits were age at first lambing (AFL), Lambing Interval (LI), Litter size at birth per ewe lambing(LSB), Litter size at weaning per ewe lambing and Ewe rearing ability per ewe lambing (RA) defined as lambs weaned per lamb born. The (co)variance components were estimated by bivariate analysis using Gibbs sampling methodology with THRGIBBS1F90 software and number of iterations, length of burn-in and sampling interval were 1,500,000, 500,000 and 250, respectively. For AFL and LI, a linear model was applied and for LSB, LSW and RA, a threshold model. Posterior means of heritability were 0.239 ± 0.053 for AFL, 0.056 ± 0.022 for LI, 0.098 ± 0.047 for LSB, 0.016 ± 0.01 for LSW and 0.019 ± 0.011 for RA. Posterior means of genetic correlation among reproductive traits ranged from -0.62 between LSB and RA to 0,82 between LSW and RA. Posterior means of phenotypic correlation between AFL and LI and each one among the others were low, close to zero. The phenotypic correlation were positive and medium between LSB and LSW (0.44 ± 0.02), medium and negative between LSB and RA (0.37 ± 0.02) and were high and positive between LSW and RA (0.98 ± 0.00). Reasonable genetic progress can be obtained in sexual precocity using age at first lambing as selection criteria. Large influences of environmental effects on LI, LSB ...As características ligadas à eficiência reprodutiva são as que apresentam maior valor econômico na maioria dos sistemas de criação de carne ovina, pois estão intimamente ligadas à disponibilidade do produto final. Estimativas confiáveis de parâmetros genéticos são essenciais para a definição de índices de seleção e para determinar a resposta correlacionada sobre as demais características presentes no índice de seleção. Assim, esse trabalho teve por objetivo estimar componentes de (co)variância e parâmetros genéticos para características reprodutivas em ovinos da raça Santa Inês. Foram utilizados dados de 4.742 ovelhas pertencentes ao Programa de Melhoramento Genético da raça Santa Inês da Associação Sergipana de Criadores de Caprinos e Ovinos em parceria com a Universidade de São Paulo. Para o estudo foram consideradas as características: Idade ao primeiro parto (IPP), Intervalo de partos (IDP), Número de cordeiros nascidos por ovelha parida (NCN), Número de cordeiros desmamados por ovelha parida (NCD) e Habilidade de criação por ovelha parida (HC) definido como a razão entre NCN e NCD. Os componentes de (co)variância foram estimados por meio de análises bivariadas, sob modelo animal linear para IPP e IDP e limiar (threshold) para as demais características, utilizando o método da amostragem de Gibbs do programa THRGIBBS1F90. O número de iterações, tamanho do descarte e intervalo de descarte considerados foram 1.500.000, 500.000 e 250, respectivamente. As herdabilidades estimadas à posteriori foram de 0,239 ± 0,053 para IPP, 0,056 ± 0,022 para IDP, 0,098 ± 0,047 para NCN, 0,016 ± 0,01 para NCD e 0,019 ± 0,011 para HC. As correlações genéticas estimadas à posteriori entre as características variaram -0,62 entre NCN e HC a 0,82 entre NCD e HC. As correlações fenotípicas à posteriori entre IPP e IDP e cada uma com as demais características foram de baixa magnitude, próximas a..

    Genetic diversity of Brazilian Brahman cattle by pedigree analysis

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    <div><p>Abstract: The objective of this work was to evaluate the genetic diversity of Brahman cattle in Brazil with pedigree analysis. Genealogical records of a subpopulation were used considering all pedigree information (Pt) and the pedigree information divided into two periods (P1, from 1994 to 2004; and P2, from 2005 to 2012) or according to the raising system (Ppt, animals on pasture; or Pst, on stable). Estimates were obtained for average inbreeding coefficients, generation intervals (GI), number of equivalent known generation (CGE), number of founders (Nf), effective number of founders (fe), effective number of ancestors (fa), and founder genome equivalents (fg). The average inbreeding coefficients were 11.97, 7.79, 11.95, 11.74, and 11.31% for Pt, P1, P2, Ppt, and Pst, respectively. Average GI was 4.4 years, whereas CGE was 3.18. The fe values were similar to those of fa, which were greater than those of fg. The fe/fa and fg/fe ratios were close to 1, which indicates no genetic bottleneck and small losses by genetic drift. The genetic diversity in the Brazilian population of Brahman breed is not significantly reduced.</p></div

    Outcomes in Newly Diagnosed Atrial Fibrillation and History of Acute Coronary Syndromes: Insights from GARFIELD-AF

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    BACKGROUND: Many patients with atrial fibrillation have concomitant coronary artery disease with or without acute coronary syndromes and are in need of additional antithrombotic therapy. There are few data on the long-term clinical outcome of atrial fibrillation patients with a history of acute coronary syndrome. This is a 2-year study of atrial fibrillation patients with or without a history of acute coronary syndromes

    Apolipoprotein B, Residual Cardiovascular Risk After Acute Coronary Syndrome, and Effects of Alirocumab.

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    Background: Apolipoprotein B (apoB) provides an integrated measure of atherogenic risk. Whether apoB levels and apoB lowering hold incremental predictive information on residual risk after acute coronary syndrome beyond that provided by low-density lipoprotein cholesterol is uncertain. Methods: The ODYSSEY OUTCOMES trial (Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab) compared the proprotein convertase subtilisin/kexin type 9 inhibitor alirocumab with placebo in 18 924 patients with recent acute coronary syndrome and elevated atherogenic lipoproteins despite optimized statin therapy. Primary outcome was major adverse cardiovascular events (MACE; coronary heart disease death, nonfatal myocardial infarction, fatal/nonfatal ischemic stroke, hospitalization for unstable angina). Associations between baseline apoB or apoB at 4 months and MACE were assessed in adjusted Cox proportional hazards and propensity score–matched models. Results: Median follow-up was 2.8 years. In proportional hazards analysis in the placebo group, MACE incidence increased across increasing baseline apoB strata (3.2 [95% CI, 2.9–3.6], 4.0 [95% CI, 3.6–4.5], and 5.5 [95% CI, 5.0–6.1] events per 100 patient-years in strata 35–<50, and ≤35 mg/dL, respectively). Compared with propensity score–matched patients from the placebo group, treatment hazard ratios for alirocumab also decreased monotonically across achieved apoB strata. Achieved apoB was predictive of MACE after adjustment for achieved low-density lipoprotein cholesterol or non–high-density lipoprotein cholesterol but not vice versa. Conclusions: In patients with recent acute coronary syndrome and elevated atherogenic lipoproteins, MACE increased across baseline apoB strata. Alirocumab reduced MACE across all strata of baseline apoB, with larger absolute reductions in patients with higher baseline levels. Lower achieved apoB was associated with lower risk of MACE, even after accounting for achieved low-density lipoprotein cholesterol or non–high-density lipoprotein cholesterol, indicating that apoB provides incremental information. Achievement of apoB levels as low as ≤35 mg/dL may reduce lipoprotein-attributable residual risk after acute coronary syndrome. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01663402.gov; Unique identifier: NCT01663402.URL: https://www
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